package com.inight.ojcodesandbox;

import cn.hutool.core.util.ArrayUtil;
import cn.hutool.dfa.WordTree;
import com.github.dockerjava.api.DockerClient;
import com.github.dockerjava.api.async.ResultCallback;
import com.github.dockerjava.api.command.*;
import com.github.dockerjava.api.model.*;
import com.github.dockerjava.core.DockerClientBuilder;
import com.github.dockerjava.core.command.ExecStartResultCallback;
import com.inight.ojcodesandbox.model.ExecuteMessage;
import org.springframework.stereotype.Component;
import org.springframework.util.StopWatch;

import java.io.Closeable;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.TimeUnit;

/**
 * docker 代码沙箱
 */
@Component
public class DockerCodeSandbox extends JavaCodeSandBoxTemplate {


    private static final String GLOBAL_CODE_DIR_NAME = "tmpCode";
    private static final String GLOBAL_JAVA_CLASS_NAME = "Main.java";
    private static final long TIME_OUT = 5000L;

    // 代码中有这些黑名单中的词 直接禁掉
    private static final List<String> blackList = Arrays.asList("Files", "exec");

    private static final WordTree WORD_TREE;
    private static final String SECURITY_MANAGER_CLASS_NAME = "MySecurityManager";
    // 到 path 中的上级目录, 不包括 class 本身
    private static final String SECURITY_MANAGER_PATH = "D:\\Java\\own\\inight-oj\\oj-code-sandbox\\src\\main\\resources\\security";
    private static final boolean FIRST_INIT = true;

    static {
        WORD_TREE = new WordTree();
        WORD_TREE.addWords(blackList);
    }


    /**
     * 覆盖掉父类的方法. 当父类执行到这个方法时, 发现子类重写了这个方法, 就会执行这个重写过的方法, 而不是父类的方法
     * 创建容器, 上传编译文件 (这一步和之前的不一样).
     * @param userCodeFile
     * @param inputList
     * @return
     */
    @Override
    public List<ExecuteMessage> runFile(File userCodeFile, List<String> inputList) {
        // return super.runFile(userCodeFile, inputList);

        String userCodeParentPath = userCodeFile.getParentFile().getAbsolutePath();
        // 3. 创建容器, 上传编译文件 (这一步和之前的不一样)
        DockerClient dockerClient = DockerClientBuilder.getInstance().build();
        String image = "openjdk:8-alpine";
        // 第一次初始化, 需要拉取镜像
        if(FIRST_INIT) {
            PullImageCmd pullImageCmd = dockerClient.pullImageCmd(image);
            PullImageResultCallback pullImageResultCallback = new PullImageResultCallback() {
                @Override
                public void onNext(PullResponseItem item) {
                    System.out.println("拉取镜像: " + item.getStatus());
                    super.onNext(item);
                }
            };
            try {
                pullImageCmd.exec(pullImageResultCallback).awaitCompletion();
            } catch (InterruptedException e) {
                System.out.println("拉取镜像失败: " + e.getMessage());
                throw new RuntimeException(e);
            }
        }
        System.out.println("拉取镜像成功");

        // 创建一个可交互的容器
        CreateContainerCmd containerCmd = dockerClient.createContainerCmd(image);
        HostConfig hostConfig = new HostConfig();
        // 限制内存
        hostConfig.withMemory(100 * 1000 * 1000L);
        hostConfig.withMemorySwap(0L); // 表示不和硬盘进行交换, 也就是不把内存中的信息写到硬盘中
        // 设置CPU
        hostConfig.withCpuCount(1L);
        // todo 设置一些安全限制, 比如读取文件啥的
        hostConfig.withSecurityOpts(Arrays.asList("seccomp=安全管理配置字符串"));
        // 设置容器挂载目录
        // 最好设置是文件的目录. 就是挂载文件. 挂载的文件不要放在根目录
        hostConfig.setBinds(new Bind(userCodeParentPath, new Volume("/app")));
        CreateContainerResponse createContainerResponse = containerCmd
                .withHostConfig(hostConfig)
                .withNetworkDisabled(true) // 禁掉网络, 代码不能操作网络
                .withReadonlyRootfs(true) // todo 限制用户不能向跟目录写文件
                .withAttachStderr(true) // 开启输入输出
                .withAttachStdin(true)
                .withAttachStdout(true)
                .withTty(true) // 开启一个交互终端
                .exec();
        String containerId = createContainerResponse.getId();
        System.out.println("创建容器id：" + containerId);

        // 启动容器, 执行命令
        // ExecCreateCmd execCreateCmd = dockerClient.execCreateCmd();
        // 4、执行命令 docker exec containtId java -cp /app Main 1 2
        List<ExecuteMessage> executeMessageList = new ArrayList<>();
        for (String inputArgs : inputList) {
            StopWatch stopWatch = new StopWatch();
            String[] inputArgsArray = inputArgs.split(" ");
            String[] cmdArray = ArrayUtil.append(new String[]{"java", "-cp", "/app", "Main"}, inputArgsArray);
            ExecCreateCmdResponse execCreateCmdResponse = dockerClient.execCreateCmd(containerId)
                    .withCmd(cmdArray)
                    .withAttachStderr(true)
                    .withAttachStdin(true)
                    .withAttachStdout(true)
                    .exec();
            System.out.println("创建执行命令：" + execCreateCmdResponse);

            ExecuteMessage executeMessage = new ExecuteMessage();
            final String[] message = {null};
            final String[] errorMessage = {null};
            long time = 0L;
            // 判断是否超时. todo
            final boolean[] timeout = {true};
            String execId = execCreateCmdResponse.getId();
            ExecStartResultCallback execStartResultCallback = new ExecStartResultCallback() {
                @Override
                public void onComplete() {
                    // 如果执行完成，则表示没超时
                    timeout[0] = false;
                    super.onComplete();
                }

                @Override
                public void onNext(Frame frame) {
                    StreamType streamType = frame.getStreamType();
                    if (StreamType.STDERR.equals(streamType)) {
                        errorMessage[0] = new String(frame.getPayload());
                        System.out.println("输出错误结果：" + errorMessage[0]);
                    } else {
                        message[0] = new String(frame.getPayload());
                        System.out.println("输出结果：" + message[0]);
                    }
                    super.onNext(frame);
                }
            };

            // 变量捕获, alt + enter 自动解决
            final long[] maxMemory = {0L};

            // 获取占用的内存
            StatsCmd statsCmd = dockerClient.statsCmd(containerId);
            ResultCallback<Statistics> statisticsResultCallback = statsCmd.exec(new ResultCallback<Statistics>() {

                @Override
                public void onNext(Statistics statistics) {
                    System.out.println("内存占用：" + statistics.getMemoryStats().getUsage());
                    maxMemory[0] = Math.max(statistics.getMemoryStats().getUsage(), maxMemory[0]);
                }

                @Override
                public void close() throws IOException {

                }

                @Override
                public void onStart(Closeable closeable) {

                }

                @Override
                public void onError(Throwable throwable) {

                }

                @Override
                public void onComplete() {

                }
            });
            statsCmd.exec(statisticsResultCallback);
            try {
                stopWatch.start();
                dockerClient.execStartCmd(execId)
                        .exec(execStartResultCallback)
                        // todo 这里设置超时时间, 过了这个时间就会往下走, 不会继续等.  但是会有无论超时与否, 都会往下执行, 无法判断是否超时
                        .awaitCompletion(TIME_OUT, TimeUnit.MICROSECONDS);
                stopWatch.stop();
                time = stopWatch.getLastTaskTimeMillis();
                statsCmd.close();
            } catch (InterruptedException e) {
                System.out.println("程序执行异常");
                throw new RuntimeException(e);
            }
            executeMessage.setMessage(message[0]);
            executeMessage.setErrorMessage(errorMessage[0]);
            executeMessage.setTime(time);
            executeMessage.setMemory(maxMemory[0]);
            executeMessageList.add(executeMessage);
        }
        return executeMessageList;
    }
}
